Merged revisions 77989 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk
........
r77989 | antoine.pitrou | 2010-02-05 18:05:54 +0100 (ven., 05 févr. 2010) | 6 lines
Issue #5677: Explicitly forbid write operations on read-only file objects,
and read operations on write-only file objects. On Windows, the system C
library would return a bogus result; on Solaris, it was possible to crash
the interpreter. Patch by Stefan Krah.
........
diff --git a/Objects/fileobject.c b/Objects/fileobject.c
index e01f38e..52d8120 100644
--- a/Objects/fileobject.c
+++ b/Objects/fileobject.c
@@ -173,6 +173,13 @@
f->f_encoding = Py_None;
Py_INCREF(Py_None);
f->f_errors = Py_None;
+ f->readable = f->writable = 0;
+ if (strchr(mode, 'r') != NULL || f->f_univ_newline)
+ f->readable = 1;
+ if (strchr(mode, 'w') != NULL || strchr(mode, 'a') != NULL)
+ f->writable = 1;
+ if (strchr(mode, '+') != NULL)
+ f->readable = f->writable = 1;
if (f->f_mode == NULL)
return NULL;
@@ -487,6 +494,13 @@
return NULL;
}
+static PyObject *
+err_mode(char *action)
+{
+ PyErr_Format(PyExc_IOError, "File not open for %s", action);
+ return NULL;
+}
+
/* Refuse regular file I/O if there's data in the iteration-buffer.
* Mixing them would cause data to arrive out of order, as the read*
* methods don't use the iteration buffer. */
@@ -701,6 +715,8 @@
if (f->f_fp == NULL)
return err_closed();
+ if (!f->writable)
+ return err_mode("writing");
if (!PyArg_UnpackTuple(args, "truncate", 0, 1, &newsizeobj))
return NULL;
@@ -949,6 +965,8 @@
if (f->f_fp == NULL)
return err_closed();
+ if (!f->readable)
+ return err_mode("reading");
/* refuse to mix with f.next() */
if (f->f_buf != NULL &&
(f->f_bufend - f->f_bufptr) > 0 &&
@@ -1018,6 +1036,8 @@
if (f->f_fp == NULL)
return err_closed();
+ if (!f->readable)
+ return err_mode("reading");
/* refuse to mix with f.next() */
if (f->f_buf != NULL &&
(f->f_bufend - f->f_bufptr) > 0 &&
@@ -1389,6 +1409,8 @@
PyFileObject *fo = (PyFileObject *)f;
if (fo->f_fp == NULL)
return err_closed();
+ if (!fo->readable)
+ return err_mode("reading");
/* refuse to mix with f.next() */
if (fo->f_buf != NULL &&
(fo->f_bufend - fo->f_bufptr) > 0 &&
@@ -1477,6 +1499,8 @@
if (f->f_fp == NULL)
return err_closed();
+ if (!f->readable)
+ return err_mode("reading");
/* refuse to mix with f.next() */
if (f->f_buf != NULL &&
(f->f_bufend - f->f_bufptr) > 0 &&
@@ -1510,6 +1534,8 @@
if (f->f_fp == NULL)
return err_closed();
+ if (!f->readable)
+ return err_mode("reading");
/* refuse to mix with f.next() */
if (f->f_buf != NULL &&
(f->f_bufend - f->f_bufptr) > 0 &&
@@ -1628,6 +1654,8 @@
Py_ssize_t n, n2;
if (f->f_fp == NULL)
return err_closed();
+ if (!f->writable)
+ return err_mode("writing");
if (f->f_binary) {
if (!PyArg_ParseTuple(args, "s*", &pbuf))
return NULL;
@@ -1665,6 +1693,8 @@
assert(seq != NULL);
if (f->f_fp == NULL)
return err_closed();
+ if (!f->writable)
+ return err_mode("writing");
result = NULL;
list = NULL;
@@ -2105,6 +2135,8 @@
if (f->f_fp == NULL)
return err_closed();
+ if (!f->readable)
+ return err_mode("reading");
l = readahead_get_line_skip(f, 0, READAHEAD_BUFSIZE);
if (l == NULL || PyString_GET_SIZE(l) == 0) {